1. Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-
Essen, Essen, Germany
2. National Reference Laboratory for Multidrug Resistant Gram negative Bacteria,
Department of Medical Microbiology, Ruhr University Bochum, Bochum, Germany
3. Hospital Hygiene, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
4. Twincore Center for Experimental and Clinical Infection Research, Hannover, Germany
5. Department of General, Visceral and Transplant Surgery, University Hospital Essen, University of Duisburg-Essen, Essen, Germany